If you go to click on the "add license" button after typing in the license key from the email and experience; "the box flashes and erases what I typed, and then nothing happens. It will not let me add the license."
You are likely having an issues due to SketchUp using IE (Internet Explorer) to display dialog windows. Could you please check for an update to your current IE installation. It is also possible that the IE settings or security settings might be causing the issue.